The structure of steps on cleaved silicon (111) surfaces was studied by scanning tunnelling microscopy. Predominantly [2¯1¯1] oriented steps were observed. Ordered regions of individual steps have unit periodicity along the step edge. A π-bonded reconstruction of the step edge was deduced from the images.

Reconstruction of Steps on the Si(111)2 x 1 Surface. R.M.Feenstra, J.A.Stroscio: Physical Review Letters, 1987, 59, 2173-6